Do we really need to put Peter through the extra work of splitting this up? The topic of the thread is WFO purchasing concerns and everything we've discussed has related to that. It's been a bit more than Reeped asked for, but, as he said, he's gotten the info he needs, has purchased the oven, and, when the oven arrives, he's planning on starting a new thread.

I'm fine with it being split, but I think the thread has pretty much run it's course and splitting it would take some work.

Works for me. Some people are sensitive about their thread, Reep doesn't seem to be. I too wouldn't want to make extra work if not needed.

They were designed to be used at much lower temperatures for bread- with a pre-heat and then retained heat baking with a closed door. We're taking a tool that was designed for something entirely different and trying to make it work for our needs. It is only a stroke of luck that, for the sake of fuel efficiency, they made the decision to go with a lower dome. Their choice of door size has no foundation whatsoever in high oven temperature thermodynamics. The door size decision was most likely based on the need for greater access for loading/unloading bread, as well as the possibility that, at some point, they might have used some kind of shelving system to fit more loaves. The door size on the FGMs has absolutely nothing to do with efficiency- at least, not within the framework of Neapolitan temperatures. When you get into Neapolitan temps, it's the Neapolitans that have done their homework, not the French. Wood has been a scarce commodity in Naples for quite some time. These ratios (dome height to oven width, door height to dome height) were born out of necessity.

Hi Scott,I am little taken back by such strong statements. Have you talked to the owner of FGM to know so much about the design and decision on the dome and door height? Do you have fuel/wood consumption for other ovens to compare with a FGM oven? I think I need to invite you for a little test cooking with a FGM. Are you up for that?

Hi Scott,I am little taken back by such strong statements. Have you talked to the owner of FGM to know so much about the design and decision on the dome and door height? Do you have fuel/wood consumption for other ovens to compare with a FGM oven? I think I need to invite you for a little test cooking with a FGM. Are you up for that?

Antoine,With all due respect...you are sounding like an attorney asking questions that he doesn't already have the answers to...

scott123

It's alright, Bob, Antoine is allowed to defend the honor of his ovens.

Antoine, were the FGMs originally designed for bread or were they not?

Burning wood creates hot air. Hot air rises and transfers heat to the dome. Cooler air drops and flows out the door. The lower the door, the greater the heat transfer to the dome. Many oven builders more knowledgeable than myself have found that a 63%ish high door allows for efficient combustion with the least heat loss through the door. This is not just me saying this.

Make the insert. If it doesn't save wood, I'll bet more than eating my hat Pick any dollar figure you want. Thousand bucks. That's how confident I am of the thermodynamics.

It is possible that a lower throat could help on the raised door, not arguing there with you. I have designed the metal piece with the FGM owner and we will get to put it to the test.

To go back to what generated my reaction, FGM has different designs for different cooking purpose and so since the beginning. The FGM bread ovens have different shapes as there is no fire in the chamber when cooking. The pizza ovens were designed to cook pizza with a lower dome and more of a round shape. Just want to make sure you have you fact straight before making statements.

I understand your thermodynamics reasoning and I don't claim that the FGM design is perfect as I am sure there is ways to improve the ovens. However I got to cook with many different ovens' brands and FGM is probably as good as it gets in terms of durability, efficiency and consistent cooking result. I just think you should try the oven before saying it is wasteful.

Let me ask you that, what brand of WFO do you cook with at home and does it have the 63% dome to door ratio?

scott123

I would beg to differ that most of the heat transferred from the fire to the brick is via hot air flow. Direct flame/coal contact and IR radiation is my best guess for the majority.

Tom, I'm not saying that 'most of the heat' is transferred by hot air. If you read my previous posts, I'm saying the minority of the heat is transferred by hot air, but it's enough to impact wood consumption and pre-heat times.

Btw, the thought just occurred to me that flame is actually part of the superheated gas equation:

Looking at it that way, superheated gas is doing the heavy lifting in the dome heating equation. To be fair, though, I have been using the term superheated air (and occasionally gas), so for the purpose of this conversation 'superheated air'=post flame gas, which as I said above, is doing the minority of the work.

scott123

It is possible that a lower throat could help on the raised door, not arguing there with you. I have designed the metal piece with the FGM owner and we will get to put it to the test.

Antoine, that's all I'm asking for.

If the low dome ovens were, indeed, designed for pizza, I stand corrected, but I still contend that they were not designed with high temp Neapolitan pizza in mind and that the dome heights just happened to turn out as being Neapolitan pizza friendly. Case in point (300C is 572F)

Tom, I'm not saying that 'most of the heat' is transferred by hot air. If you read my previous posts, I'm saying the minority of the heat is transferred by hot air, but it's enough to impact wood consumption and pre-heat times.

That's not what it sounds like when you write "IR and conduction are big contributors to floor (and, to a certain extent, wall) heat, but dome heat relies a great deal on convection."

My experience leads me to believe that IR is much more important than convection with respect to heating the dome and walls. This is why I question your assumptions. The additional hot air has so little energy relatively speaking, has such poor heat transfer characteristics, and is exposed to such a small incremental % of the total oven area, I just don't see the 25% reduction in heating time you are claiming.

Logged

"We make great pizza, with sourdough when we can, commercial yeast when we must, but always great pizza."Craig's Neapolitan Garage

My experience, I have tried countless Oven from barrel ovens to Stefano Ferraro I Have made 1000's and 1000's ( well approaching 2000 I think?) in my mobile, what I believe is a forno bravo. I made just 75 in the FGM 950B I am Happy FGM got lucky ? with the dome height, and Happy I was lucky enough to not loose too much heat. 1st pic is heat up 2nd full on cooking see the nice light flame going accross the dome? Flame touching dead space? superheated schmeeted gases. As far Scott's heat up time comments I can also say, oven did not heat up as quickly as my Mobile I feel because the brick finish and refractory are different, not that it was going out the door or up the chimney? I was pushing the heat up because I was a little late (as usual) Once she got in the zone I will say it again, cooked like a dream and maintained heat nicely and used very little wood ? But I did not have my Abacus to calculate the consumption. We are talking about a home oven here I get free wood and the average homeowner (especially not a member here ) who has money to spend on a WFO will be very happy with the joy of cooking in a wfo I just don't think the extra 3 sticks or 30 min +- is on their mind ? I have to say sure has been interesting and great that some people are that into it is very cool ! (or Hot) Scott, I will be going to visit Antione you would be welcome to come along and check things out

scott123

Experience... absolutely. And when someone posts their wood usage and pre-heat times with a lower door FGM, I will defer to that experience completely. Until then, though, this is largely theory.

Theory and history. I'm well aware that some of Marco's beliefs are not universally accepted and I also believe that Neapolitan oven builders can be wrong. At the same time, though, I strongly believe that we can learn from the Neapolitans and that, without evidence to the contrary, when it comes to oven design, the Neapolitans get the benefit of the doubt. Just because we don't have any Italian oven builders on this forum doesn't mean that their opinions don't carry weight. If their oven has a particular specification, and we can find a relatively easy way to match it, then we definitely should, until it is proven as being inferior.

Between French (or any other nationality) oven builders baking pizza at 600 degrees and Neapolitan oven builders with more than a century of making the exact pizza that we're all striving for, I will ALWAYS defer to the Italians until I see hard evidence to the contrary.

The low doors on all Neapolitan ovens are not there by chance. They're not an aesthetic decision. They are their for a reason. Until they are completely proven as unnecessary, I will continue to fight tooth and nail for them.

The Italians aren't always right, but until proven otherwise, I defer to their experience.

Since they all use the same cast door frame, maybe a hundred years ago there was only one company making those doors so they all used it and now it is tradition like so much of the Neapolitan pizza religion.

scott123

Oh, okay Your post does ring true in regards to one aspect, though- that the Neapolitans might very well be blindly following tradition. Tradition always has to be questioned. That's a given. But until we have data proving otherwise, it should get the benefit of the doubt.